Flying Ruler is a tape measure, ruler, protractor and a goniometer (angle-measurer). It is four devices in one app, providing you with the quickest way to measure a distance or an angle.
The Flying Ruler app allows you to measure in the most original way: by just moving your device from one point to another.
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*** Top 5 in 79 countries in the App Store utilities category ***

The secret of the program is that it is based on the principles of the inertial navigational system (INS): the position of the device is determined with the help of the accelerometer and the gyroscope. You can not only measure an object but also the distance between two walls.

*** Only on iOS ***

To try this technology for free you can install the app "Move to measure - Goniometer". This free app measures the angle as you move the device.


Editor's Choice - 148Apps


"I was impressed with Flying Ruler’s accuracy. It works quickly and effectively", "It’s the perfect addition to anyone’s app collection" -- 148apps 4.5 / 5 (MUST HAVE)

"I literally said “wow!” when I first used this app and I think it’s a truly impressive marvel of mobile technology", "The Flying Ruler Rules" -- AppPicker (Cons: there is nothing negative to say about this app)

"This thing is awesome." --


You can choose either inches or centimeters.
The app has different modes so you can choose which mode is better and easier to use on each occasion. You can measure with the body of the device in one mode or with a virtual ruler in another. You use the same methods to measure angles as the app allows you to measure angles both on a surface area and between surfaces through space.
The app also allows you to save a measurement by taking a photograph of the measurement and mark the place that was measured.
Don’t forget to show your friends and colleagues how the app works – believe us, they will be impressed.


We took 100 consecutive measurements and got these results:

On iPhone 6 Plus:

∙ Mean squared error - 0.49%
∙ Maximum inaccuracy - 1.2%
∙ Number of measurements where inaccuracy was within 1% - 93

On iPhone 4:

∙ Mean squared error - 1.02%
∙ Maximum inaccuracy - 3.0%
∙ Number of measurements where inaccuracy was within 1% - 65, within 2% - 96

The accuracy of measurements depends on the device, however the error rarely exceeds 3%. You can always increase accuracy by making a series of measurements. If you make a series of measurements, the degree of error is usually 1% or less.

The app cannot replace a ruler completely as a ruler has a fixed degree of inaccuracy (half of the smallest increment) but it is useful for getting an approximate measurement without a ruler as, remember, your device is always with you.

In some cases, when you know that the distance is some kind of standard size, you can say with a degree of certainty that you will get an accurate result. For example, if you measure a piece of furniture, which is nearly always a length in multiples of 6″, and you get 2′ 11 1/2″ then more than likely the real result is 3′. Or if you are using the metric system, if you get 61 cm then more than likely the real result is 60 cm.

Angles can be measure with the app to an accuracy of one degree so the app can easily take the place of a protractor or a goniometer (angle measurer).


What’s New

Version 3.0

- the user interface for switching modes of measurement is changed
- VoiceOver support is improved
- new inertial spec calibration for increased accuracy (when necessary)
- improved performance on the iPhone 6S and 6S Plus
- optimized for iOS 9
- other minor alterations and improvements

Ratings and Reviews

4.0 out of 5
155 Ratings

155 Ratings

Nariosan ,

The one to get!

Out of 6 measurement apps I downloaded this is the only one I kept. Here's why
#1 it works. It actually measures any distances pretty accurately.
#2 ease of use/ versatile:
Drop phone at starting point and press button, pick it up when it turns green and drop phone off at end point. Whether inches or feet away. It doesn't matter.
#3 truth in advertising. All others say free and then you find you can't use them without paying money. This one says $1.99 up front. No tricks.
#4 cheapest and most accurate. The others use things like photos and they are just not as accurate as this one.
Improvements? Of course I'd like it better if it was free. But you get your money's worth. What measurement tape cost less and goes longer? And you always have it with you.
PS: the calibration method is so simple it may confuse you. Just drop phone on a flat surface as shown/ oriented on drawing and it automatically detects it and places a check mark. Repeat till all 6 drawings have a check mark.
Just pay attention to the drawing: which way is the button? (up, down, face down etc. )

Docj ,

Fantastic technology

I was looking all over the App Store for some measuring app to measure between walls and distances. The only thing out there were stupid apps were you had to hold your finger down and slide the phone hoping your fingers don't slide off the screen. This app is using technology to basically lift the phone and put it down from one point to another and the accuracy is extremely good but of course it will never equal a measuring tape. I can imagine using this while I'm out and about and needing to measure something in the store

lars b amble ,

this should be the only measurement app on the app store

it’s a shame i had to wade through a bunch of crap apps in the measurement category before finding this one as this is clearly the only one worth getting. i was unsure about dropping the 2 bucks for it initially but now i’m glad i did. very well designed, great and extensive use tutorials built right in, works exactly as it says and incredibly accurate. i only hope adding another review bumps it up a bit higher on the search list when people search for measurement apps cause this deserves to be the first, if not the only one that shows up. well worth getting, perfectly designed, works very well. really this exceeds expectations and goes above and beyond in all areas. as a designer myself, i give the team behind this app mad kudos. good work.


51.7 MB

Requires iOS 7.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French, German, Italian, Japanese, Korean, Russian, Simplified Chinese, Spanish

Age Rating
Rated 4+
© 2013-2016 Alexey Brilev


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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